USAF plans F-15 modernization, but pilots want better displays

17 August, 2012

SOURCE: Flight International

BY: Dave Majumdar

Washington DC

The US Air Force is planning a host of upgrades for its fleet of Boeing F-15Cs and F-15Es, but pilots say that without upgraded displays, they will not be able to take full advantage of those enhanced systems.

On the two-seat multirole F-15E Strike Eagle, the air force is planning to add the new Raytheon APG-82(V)1 active electronically-scanned array (AESA) radar, a new advanced display core processor II (ADCP II) mission computer, a new electronic warfare system dubbed the Eagle passive/active warning and survivability system (EPAWSS), a digital video recorder, Mode 5 identification friend or foe (IFF), and a joint helmet mounted cueing system (JHMCS) for the front seat, says a senior air force official at the F-15 system program office (SPO) at Robins AFB, Georgia. The aircraft will also receive a series of software block updates.

The air force plans to furnish the single-seat F-15C air superiority fighter fleet with a similar upgrade. The F-15C is already receiving the Raytheon APG-63(V) 3 AESA, but it will also receive the ADCP II, EPAWSS, Mode 5 IFF, a new flight data recorder, a satellite communications (SATCOM) radio, and a new digital video recorder, the F-15 SPO official says. The F-15 will also receive a series of software block updates.

Pilots applaud the improved sensors, but point out that without a major overhaul to the aircraft's displays, they will not be able to take full advantage of those new systems. "Those look like great upgrades. The part I see that is lacking is in the displays," says one highly experienced former F-15 pilot. "You have these phenomenal subsystems, but if you can't provide [sensor data] in a meaningful way to the operator, it doesn't matter."

The radar display on the F-15C is particularly problematic. "The F-15C has a phenomenal radar, but the info is displayed on a tiny four by four [inch] scope," the pilot says. Even the F-15E, which has a much more modern glass cockpit, will not be able to fully utilize the information generated by the new sensors without further modernization.

The USAF is not currently considering adding, for example, the large area display or decoupled cockpits that Boeing is offering to international F-15E customers. "However, we continue to look for opportunities to leverage to meet the warfighter's needs," the F-15 SPO official says.

The APG-82 development effort for the F-15E is continuing, the F-15 SPO official says. The new radar marries the AESA antenna from the APG-63(V) 3 with the backend electronics from the Boeing F/A-18E/F's Raytheon APG-79 AESA radar-currently in service with the US Navy. "Operational testing will start in March 2013," the official says. "The first production installation is scheduled for early fiscal year 2014."

Meanwhile, the air force has started planning for the development and integration of the EPAWSS. The service hopes to award an engineering and manufacturing development (EMD) contract in the second quarter of fiscal year 2015, the official says.

To take better advantage of the new radar and electronic warfare systems, and also to enable further upgrades, the F-15 must integrate the ADCP II computer. The air force hopes to start development of the ADCP II with a "Milestone B" decision in November 2012, the F-15 SPO official says. The first F-15E installation is planned for the fourth quarter of fiscal year 2016 while the F-15C will receive the new computer in the fourth quarter of fiscal year 2017.

The USAF also hopes to add an infrared search and track (IRST) capability to the F-15C, which could significantly boost the air-to-air capability of the venerable air superiority fighter. "The IRST program will restart in fiscal year 2015," the official says. But "the F-15E will not receive the IRST" because it is not primarily tasked with air-to-air missions.

Further modernization is a foregone conclusion as both versions of the F-15 are expected to remain in USAF service into the 2030s. Fortunately for the air force, the F-15 airframe is robust and should be able serve well into the future, the F-15 SPO official says.

"There is currently no projected requirement for a major structural mod program. Numerous structural improvements have been incorporated throughout the life of both F-15C and E models," he says. "Many parts have been redesigned to eliminate structural issues identified during service."

One of the unique features of the F 15 is that "it has very robust programmed depot maintenance (PDM) which includes a complete wing overhaul." The aircraft's structure will continue to be sustained through this PDM process, the F-15 SPO official says.

But the USAF is also working to increase the F-15's service life though structural testing.

"Previous F-15E full scale testing successfully demonstrated 16,000 flight hours of operational usage with no catastrophic failures or evidence of life limiting fatigue issues. The current fleet average is approximately 9,000 hours," the official says. "A contract for additional testing was awarded in [fiscal year 2010] to recertify the F-15E structure for service to 2035 based on current/projected flying hours and usage severity." Testing in the Strike Eagle should be completed by September 2015.

F-15C full scale testing has already demonstrated 18,000 flight hours of operational usage "with no catastrophic failures or evidence of life limiting fatigue issues. The current fleet average is approximately 8,600 hours," the F-15 SPO official says. The air force awarded a contract for additional testing on the jet in fiscal year 2009 to recertify the F-15C's structure to push its service life out to 2030. That is "based on current/projected flying hours and usage severity," the official says.